We are aware of that. :) Apparently Your (the community) help can speed up the process.
We plan on checking all of our games and than officially add "Windows 7 Compatibility" to our site. It might happen that some games will take longer than that to fix. Others might by impossible to fix. But do not despair - we'll keep you informed about what has been positively tested and verified as well as to what titles we cannot guarantee compatibility (lets hope that it won't happen) .
Only in case that you need the fixed version. Re-downloading your games with fixed compatibility with Win7 while you use XP/Vista will be pointless... Unless stated otherwise. :P You know how it is. :) We might coincidently fix something else - but again, we'll keep you updated.
One of the most interesting part of working at GOG.com is that we never say never. The only valid question is when do we say "now". ;) Linux / OS X definitely won't be supported for the time being but some things might change in the future. and we all know how it is with the future - future is unpredictable.
That will be a business decision. Maybe when Microsoft releases its next operating system (Windows 8 or some other catchy name) such decision will be made. But for now don't be surprised if our games continue to work on XP. :D

We'd like everyone to feel better, not only those using Win7. ;)
When Microsoft sees XP dead and stops supporting it we might come to a similar conclusion. After all GOG.com is about playing old games on new computers. And with the flow of time "old" as well as "new" will change. But as I have said - the higher ups will decide what's best for the company. and in case of GOG.com we are much dependant on our customers. So do not panic nor fear GOG.com loosing XP compatibility in the near future.
Unfortunately our hassle-free policy includes recompilation of our installers and not releasing patches. In this way you only have to download one package and not try to make with different versions of different patches -so similar to the well known dll-hell. :)
Sorry but for now there is not a single one title that we have released without properly fixing the compatibility. Should such case arise than we'll wonder what to do.
But it troubles me... Why do you believe that something like that might happen? I thought that everyone will comment "Oh no! That's impossible. Surely you will fix everything." :P:P
Have faith in us. :) Personally I believe that we will ensure Win7 compatibility for every game in our catalogue. I'm mature enough to know that some things might go wrong and not according to the plan... But than I'm also stubborn so I refuse to give up just because something might go wrong. Fortunately that's the way GOG.com works. ;)